- 10 - 25 mins
- Experimentation, critical thinking, prediction, colour mixing
- Minimal mess
- Easy!
Want a super easy experiment, that is quick to prepare, has instant results and has a rewarding and very colourful conclusion? Then you must try this grow a rainbow experiment!
Learn about chromatography (separating a mixture of chemicals), capillary action theory (water moving upward through paper towel) and colour mixing, whilst watching a rainbow come together right in front of your eyes. Both adults and children alike will be mesmerized with this one!
Did you know? Science related experiences are great for young children, particularly preschool aged because they are inquisitive, naturally curious, and open-minded. It is a great way to bring different levels of learning, important learning skills such as questioning, predicting, experimentation and the use of trial and error, & cause and effect principles.
What you will need
- Paper towel
- Coloured washable markers
- 2x clear cups
- Scissors
- Water
Activity steps
Fold a piece of absorbent paper towel in half and trim it down to 7.5cm in length. Too long and the rainbow may not connect.
- At each end of your paper towel, use your coloured markers and draw some thick coloured rectangles. Use a different colour of the rainbow (red, orange, yellow, green, blue, indigo and violet) for each rectangle and make sure you apply lots of ink to make sure there is enough ink to be absorbed and travel across the paper towel.
- Grab your cups and fill each with water ¾ of the way full.
- Now place the cups parallel and close to each other and put one end of your paper towel in one cup, and the other end in the other cup. Make sure only the ends are touching the water. If they are too deep the colour may leak into the water instead of travelling across the paper towel.
- Wait and watch the colours travel up and over the paper towel from one side to the other, meeting in the middle and creating a beautiful rainbow!
Questions you might like to ask before/during the experience:
- What do you think might happen when we put the paper towel in the water?
- What do you notice?
- Why do you think the colour moves the way it does?
- What do you think will happen when the colour meets in the middle?
- What do you know about rainbows?
To learn the science behind the activity and learn about chromatography head to the website listed below.
Extension:
- Perhaps you could explore with different colours. Try using different mixtures of colours, do you get the same effect? What if you used dark colours opposed to bright colours?
- Try experimenting with a variety of drawing resources. Do crayons, pencils and paint have the same effect?
- Perhaps you could hypothesis, and graph how long you think it will take to grow a rainbow. Use a timer- how long did it take? Perhaps you could set up a variety of experimentation stations with different lengths of paper towel. Will the shorter piece of paper towel be quicker?
Learning Outcomes
- Nurture curiosity
- Foster critical thinking
- Engage in basic science skills- questioning, prediction, experimentation
- Have a basic understanding of capillary theory
- Engage with colour theory- colour recognition and colour mixing
Reference sites
We would like to acknowledge these amazing sites that have inspired us to create this activity. Thank you!